1. Field of the Invention
The present invention relates to a post and rail system which may be used as a railing system for decks, or may be used as fencing. The system makes use of extrudable plastic posts and rails, and provides improved means for supporting the posts which include a pipe projecting upwardly and a special spacer for locating the post on the pipe. The supporting pipe may be a length of galvanised steel pipe commonly available from hardware stores.
2. Prior Art
Hollow posts, often made of plastic materials, are known for use in deck railing systems, and for fences. In the decking field, commonly the posts have been connected directly at their sides or bases to wooden parts of the decking, for example by bolts, but such connection means lack firmness and strength.
In some cases, both for rails and fencing, hollow posts have been supported by a rigid support member having a lower portion securely held by a ground fixture or part of the decking, and having an upper portion extending within the post.
The following patents show examples of such constructions:
U.S. Pat. No. 3,910,561, which issued Oct. 7, 1975 to Fornells;
U.S. Pat. No. 4,461,461, which issued Jul. 24, 1984 to Caron;
U.S. Pat. No. 4,702,459, which issued Oct. 27, 1987 to Moschner;
U.S. Pat. No. 4,809,955, which issued Mar. 7, 1989 to Veilleux;
U.S. Pat. No. 4,892,292, which issued Jan. 9, 1990 to Russell;
U.S. Pat. No. 4,958,807, which issued Sep. 25, 1990 to Wylie;
U.S. Pat. No. 5,255,899, which issued Oct. 26, 1993 to von Grozny,
U.S. Pat. No. 5,617,697, which issued Apr. 8, 1997 to Erwin;
U.S. Pat. No. 5,704,188, which issued Jan. 6, 1998 to Coulis;
U.S. Pat. No. 5,709,366, which issued Jan. 20, 1998 to Speece;
U.S. Pat. No. 5,722,205, which issued Mar. 3, 1998 to Gannaway; and
U.S. Pat. No. 5,862,642, which issued Jan. 26, 1999 to Erwin;
Similar means for supporting posts, although not fence posts, have been shown in the following patents:
U.S. Pat. No. 4,520,985, issued Jun. 4, 1985 to Blumenthal;
U.S. Pat. No. 4,939,877, issued Jul. 10, 1990 to Claffey; and
U.S. Pat. No. 5,305,976, which issued Apr. 26, 1994 to Blanchard.
The Erwin ""697 patent shows a hollow plastic deck post supported by an internal square metal tube; this tube only contacts one side of the post and so gives limited support for the post. The Erwin ""642 patent shows an improved design where the internal support is shaped so as to contact two corners of the post. This support is a special trapezoidal metal element, and is used along with wooden blocks; i.e. the support is not a commonly available hardware item.
The patents to Caron and Russell are similar to each other, and both show hollow circular posts supported by internal support members in the form of steel pipes or bars fixed to a base, the posts being joined to the pipes or bars by spacers in the form of plain tubular members. The rails are attached to the posts by fittings which resemble right angled pipe fittings. The tubular spacers provide little space between the circular posts and the pipes.
The Fornells, Moschner, and Wylie patents also show hollow plastic posts supported by a rod or pipe, but here the means connecting each rod or pipe to the post are integrally formed with the post, so that the post is not a simple tube. In Moschner the post is not extrudable, and needs to be molded.
The patent to Fornells also shows a relatively complex arrangement for attaching the rails to the posts, which allows the angle of inclination of the rails to be varied.
The von Grozny patent shows a hollow post supported by a ground-engaging spike via a settable material which is poured into the post; the settable material is required to take up a large amount of space within the post. Coulis shows a spring clip formed of wire for spacing a support pole inside a hollow post, which would be a more expensive item to make than a simple extrusion.
Much of this prior art shows constructions which are somewhat complex and expensive, especially in relation to the connections between posts and rails, and in requiring special parts which cannot be extruded.
Another problem with much of the prior art is that the parts which need to be provided to the installer include special internal support means. Such support means may be of special design, as shown in the patents of Speece, Gannaway, Veilleux, Erwin ""642, Blumenthal, and Blanchard. In other cases, a simple tube or spike may be used, as in Caron, Russell, or Claffey, but this must fit exactly into the post part, making it doubtful if a common off-the-shelf pipe or spike would be satisfactory.
The present invention provides a construction in which cost is minimised, firstly by having major parts of the railing or fencing system, including the spacers which locate the posts on a supporting tube, formed of simple extrudable parts, usually of plastic, and secondly by having very simple connections between the posts and rails which do not require any special components. Furthermore, the parts allow the use of internal supports means, specifically metal pipes, which do not have to be a precise fit in the extruded parts, and so can be pipes of the type commonly available from hardware stores.
In the present invention, hollow (i.e. tubular) extruded plastic posts are used which have an internal cavity of constant cross-section; usually the posts are square. The posts are supported by internal support members in the form of cylindrical metal pipes having an upper portion extending within an internal cavity of one of the posts while a lower portion of the same pipe extends below a lower end of the post and is adapted to be fixed in vertical position. The rails, which are narrower in plan view than the posts, are connected to the posts simply by routing apertures in the side walls of the posts. The routing may be done by an installer, in accordance with site or customer requirements.
The nature of the joints between connecting posts and rails necessitates that, to prevent dislocation of the joints, there be sufficient overlap between the outer sides of the posts and the inner ends of the rails. If, for example, the simple tubular spacers used by Caron or Russell were to be used with apertures in the post walls to receive ends of the rails, the rails would not project sufficiently far into the posts to be secure.
Accordingly, the present invention also provides a spacer for connecting the support members to the posts in a manner which allows rails to project sufficiently into apertures in the post sidewalls to be secure. The spacer is integrally formed by extrusion of plastic material member and has:
a tubular portion suitable for providing an interference fit onto the supporting pipe, and longitudinal ribs projecting outwardly from the tubular portion and suitable for firm engagement within the side wall of one of the posts and which provide a clear space of at least one-half inch between the post side wall and the pipe at the locations of apertures made in the post to receive the rails.
In order to provide a suitable firm engagement between the pipe and the spacer, the tubular portion of each spacer has circumferentially spaced internal surface portions suitable for contacting the pipe at spaced locations around the pipe, the tubular portion having flexibility to allow distortion of its shape so that the internal surface portions can positively locate on pipes of slightly differing dimensions. Preferably, four of the internal surface portions are spaced generally evenly around the internal surface of the tubular portion and each are positioned between a pair of the longitudinal ribs.
The tubular portion may be cylindrical, in which case the internal surface portions are ribs projecting inwardly from the tubular portion. Alternatively, the tubular portion, when seen in cross-section, may be in the form of a hollow square with the ribs projecting from the corners of the square, and central areas of the sides of the tubular portion may provide the internal surfaces which contact the pipe. In each case the distortion which occurs when the internal surfaces are pushed outwardly by contact with the pipe have little effect on the diameter of the tubular portion at the bases of the ribs.
The longitudinal ribs extending outwardly from the tubular portion all lie in mutually perpendicular planes, and preferably the ribs each have an outer edge with at least one side flange, each side flange having an outer surface lying at an angle of between 45xc2x0 and 90xc2x0 to the respective rib, the side flanges being solid in cross-section and having a thickness of less than 0.15 inches to allow the side flanges to bend by contact with an inside surface of the post cavity and thus to provide an interference fit therewith. The flanges preferably have a thickness of between 0.08 and 0.13 inches.
Where the spacer is for use in a post having a cavity of square cross section, the outer surface of each flange lies at an angle of between 50 and 65xc2x0 to the respective rib. Preferably each rib has a pair of flanges in arrowhead formation, and the angle between the outer surfaces of the adjacent flanges is between about 100 and 130xc2x0, and usually between 110 and 120xc2x0.
A similar spacer may be used for posts of circular cross section, but here the side flanges will project from the ribs at an angle close to 90xc2x0, so as to be slightly bent when forced into the circular post.